1. Field of the Invention
The present invention relates to printer maintenance, and, more particularly, to an apparatus and method for detecting an amount of discharged ink to control the maintenance of a printer.
2. Description of the Related Art
Inkjet printers generally have a head with a plurality of nozzles, each of which is arranged in a desired printing position, and printing is achieved by discharging ink through the nozzles. A heater, which is positioned near nozzles, heats the ink so that the ink is discharged through the nozzles during printing. Driving pulses are applied to the heater to discharge the ink through the nozzles.
Printing quality of an inkjet printer depends on the states of the nozzles. In other words, if the nozzles are not used for an extended period of time or if ink is continuously discharged, the nozzles may become clogged or contamination of ink may occur, which may result in a deterioration of printing quality. Thus, a general inkjet printer performs maintenance operations, i.e., spitting, wiping, and capping operations, before or during printing to prevent clogging of nozzles or contamination of ink. That is, for smooth flow of ink through the nozzles, the general inkjet printer discharges ink in the spitting operation, wipes the nozzles in the wiping operation, and caps the nozzles in the capping operation.
FIG. 1 illustrates conventional maintenance operations performed for several situations. When a printer is reset or a new head is installed in a printer, maintenance is performed, including a wiping action that is performed once and a spitting action that is performed a predetermined number of times “A,” depending on the manufacturer of the printer. In FIG. 1 at 100, the wiping and spitting sequence is performed twice.
If a user gives a maintenance command to the printer, the wiping action is performed once and the spitting action is performed a predetermined number of times “B,” depending on the manufacturer. At 110 of FIG. 1, the wiping and spitting sequence is performed three times.
If a printing command is given to the printer, the wiping action is performed once and the spitting action is performed a predetermined number of times “C,” depending on the manufacturer. At 120 of FIG. 1, the wiping and spitting sequence is performed once before printing is performed on each page.
At 130 of FIG. 1, after printing is finished on a designated line, the wiping action is performed once and the spitting action is performed a predetermined number of times “X” during color printing, and the wiping action is performed once and the spitting action is performed a predetermined number of times “Y” during mono printing.
At 140 of FIG. 1, after a predetermined period of time elapses in a machine idle state, the same maintenance operations are carried out as those at 100 of FIG. 1.
FIG. 2 is a flowchart explaining a process of performing conventional maintenance operations.
When a printer is reset due to the supply of power to the printer or the installation of a new head in the printer, in step 200, basic maintenance operations are performed for the nozzles of the head at 200 that are the same as the operations performed at 100 of FIG. 1.
At 210 of FIG. 2, if a user gives a maintenance command to the printer during printing using a command contained in printer driver software to improve printing quality, then, at 220 of FIG. 2, maintenance operations are performed that are the same as the operations performed at 100 of FIG. 1.
At 230 of FIG. 2, the same maintenance operations performed at 120 of FIG. 1 are performed before printing starts on each page to maintain uniform printing quality.
After printing is finished or the printer interfaces with a computer for a predetermined period of time, the same maintenance operations performed at 140 of FIG. 1 are performed at 240 of FIG. 2.
In the above-described maintenance operations, to control the maintenance operations, an amount of ink is measured by counting the pulses for driving the heater. However, if the heater operates abnormally, even when ink is not discharged, pulses may still be counted to measure the amount of discharged ink, resulting in performance of maintenance operations. As a result, improper maintenance operations may be carried out. For example, after printing every other line, spitting and wiping are carried out. However, if a large amount of ink has already been discharged, no ink may be left for the subsequent maintenance operations. Thus, maintenance operations such as spitting may not be performed even when required, and thus uniform printing quality may not be obtained on each page.